Cardiac function in experimental mitral stenosis.

The results of S5 combined right and left heart catheterizations in normal dogs and dogs with experimental mitral stenosis are presented. Animals lived as long as 10 months with elevated pulmonary vein pressures. Pulmonary vein pressures in excess of 15 mm. Hg were associated with mitral orifice areas which were smaller than those found in normal animals. Elevation of pulmonary vein pressure was associated with a decrease in the pulmonary vascular pressure gradient, with no change in cardiac index as measured and with a decrease in calculated pulmonary vascular resistance.